Windmill



FIG. 1 is a first side elevation view of a windmill showing our new design;

FIG. 2 is a second side elevation view thereof;

FIG. 3 is a top perspective view thereof;

FIG. 4 is a bottom perspective view thereof; and,

FIG. 5 is a bottom plan view thereof. 

CLAIM The ornamental design for a windmill, as shown and described. 